1. Field of the Invention
The present invention relates to a bend alignment type liquid crystal display apparatus.
2. Description of the Related Art
A bend alignment type liquid crystal display apparatus includes a liquid crystal layer in which liquid crystal molecules have a splay alignment in an initial alignment state. After transition from the splay alignment to bend alignment of the liquid crystal molecules, the alignment state of the liquid crystal molecules in the bend alignment is controlled.
The bend alignment type liquid crystal display apparatus includes a liquid crystal layer sealed in a gap between a pair of substrates opposed to each other. Inner surfaces of the substrates have been subjected to aligning treatment to align the liquid crystal molecules of the liquid crystal layer in a splay configuration. The liquid crystal molecules of the liquid crystal layer have a splay alignment in which the major axes of the molecules align in the direction of aligning treatment. The inner surfaces of the substrates are provided with opposing electrodes. Between the electrodes, an electric field to cause the liquid crystal molecules to transit from the splay alignment to the bend alignment is applied at the start, and a driving electric field corresponding to image data is applied after the start.
At the start, in the bend alignment type liquid crystal display apparatus, an electric field which causes the alignment transition is generated between the electrodes of the substrates to transit the alignment of the liquid crystal molecules from the splay alignment to the bend alignment. After that, a driving electric field corresponding to the image data is generated between the electrodes to control the alignment state of the liquid crystal molecules in the bend alignment, thus displaying an image.
In the bend alignment type liquid crystal display apparatus, to cause the liquid crystal molecules to transit from the splay alignment at the start to the bend alignment within a short period of time at a low voltage is sought for.
For this purpose, conventionally, to use a liquid crystal material having a small ratio K33/K11 of a splay elastic constant K11 to a bend elastic constant K33 (see Jpn. Pat. Appln. KOKAI Publication No. 8-87013) and to subject the inner surface of at least one of the substrates to treatment that changes the rising state of the liquid crystal molecules among regions upon application of an alignment transition voltage (see Jpn. Pat. Appln. KOKAI Publication No. 2000-66208) have been proposed.